One holding the boat up? (5)
I believe the answer is:
davit
'boat up?' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Perhaps you can see a link between them that I can't see?
'one holding the' is the wordplay.
'one holding' becomes 'davi' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'the' becomes 't' (the is pronounced as a 't' sound in some dialects).
'davi'+'t'='DAVIT'
Can you help me to learn more?
(Other definitions for davit that I've seen before include "device for lowering boat" , "Lifeboat crane" , "Crane-like device for suspending or lowering ship's boats" , "nautical equipment" .)